JPH05199690A - Insulating system for rotor core - Google Patents

Abstract

PURPOSE:To improve the mechanical and dielectric strengths of the title system by a winding prepreg tape composed of reconstituted mica around a conductor and further winding a glass flake prepreg tape lined with glass cloth around the conductor, and then, hot forming the conductor in a metallic mold. CONSTITUTION:After a prepreg tape 2 composed of reconstituted mica is wound a prescribed number of times around a conductor 1 having a rectangular cross section, a glass flake prepreg tape 3 is further wound a prescribed number of times around the conductor 1. The tape 3 is formed by putting glass flakes 5 between two layers 4 and 6 of glass cloth. The glass flake content in the insulating tapes 2 and 3 is increased by thermally hardening the conductor 1 wound with the tapes 2 and 3 in a metallic mold. Therefore, the mechanical and dielectric strengths of the insulating tapes can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage rotating machine coil insulation system produced by winding an insulating tape, and particularly to an insulation system suitable for a coil requiring high voltage and mechanical strength. Regarding

[0002]

2. Description of the Related Art A conventional rotating machine coil insulation system is
An insulating system is constructed by using a dry insulating tape consisting of glass cloth and laminated mica or flake mica and impregnating a thermosetting resin in vacuum and then thermosetting, or by thermoforming using a thermosetting resin prepreg insulating tape. Was. In this case, the insulating strength is made of laminated mica and the mechanical strength is made of flake mica or glass cloth.

[0003]

However, flake mica has a slightly low dielectric strength and mechanical strength, and glass cloth has a weak point that it has very low dielectric strength because it has no barrier performance against a discharge streamer. Sufficient mechanical and insulating strength was not obtained with the composite structure with mica.

[0004]

Therefore, in the present invention, a glass flake having high mechanical strength and high dielectric strength is used as an insulating material to produce an insulation system for a high-voltage coil having a high voltage resistance and a high mechanical strength. It has become possible.

[0005]

[Function] Since glass flakes are thin pieces of inorganic glass,
High dielectric strength and good partial discharge resistance. Further, due to the flake shape, it has a good discharge streamer barrier performance. Further, since it is glass, it has high tensile strength. Therefore, by laminating it like laminated mica, an insulating tape having high mechanical strength and high insulation performance can be obtained.

[0006]

<Embodiment 1> An embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a cross-sectional view of the coil insulation system of the present invention constructed with a prepreg tape. The mica prepreg tape 2 is first wound around the conductor 1, and the glass flake prepreg tape 3 having the structure shown in FIG. 2 is wound on the conductor 1 a predetermined number of times and heat-cured and molded in a mold. The glass flake prepreg tape 3 is obtained by disposing glass flakes 5 on a glass cloth 4 in a dispersed manner, further adhering the glass cloth 6 thereon, and then impregnating with an epoxy resin and semi-curing.

The relationship between the bending strain and the breakdown voltage of the coil insulation system of this embodiment is shown in FIG. 3 in comparison with the conventional insulation system consisting of only mica. In the conventional mica-only system, the breakdown voltage is greatly reduced at a bending strain of 0.3% or more, but the insulation system of the present invention is 0.5.
It has the effect of maintaining a high breakdown voltage up to a bending strain of at least%.

Example 2 An example of another prepreg tape of the present invention is shown in FIG. The glass flakes 5 are dispersedly arranged on the glass cloth 4, impregnated with an epoxy resin and semi-cured.

In addition to the glass flake prepreg tapes mentioned above, a dry tape not impregnated with epoxy may be used, and the insulation system similar to the above may be constructed by winding the tape around the conductor 1 and then impregnating the epoxy with vacuum. In this case, since no void is generated, a more reliable insulation system can be obtained. Alternatively, a coil can be prepared by winding an insulating tape backed with a glass cloth, which is a mixture of glass flakes and mica flakes.
In this case, since it is not necessary to prepare two tapes, glass flakes and mica tape, the tape winding operation is simplified. Also, as the backing material for glass flake tape,
In addition to glass fiber cloth, organic high-strength fibers such as liquid crystal polymers and inorganic high-strength materials such as alumina fibers can be used.

[0010]

According to the present invention, when the coil insulation system is constituted by the prepreg tape, the content of the glass flakes is increased, so that the barrier effect against the discharge streamer is increased and higher dielectric breakdown strength can be expected.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of the tape of the present invention.

FIG. 3 is a comparison diagram of bending strain-fracture characteristics of the present invention and a conventional example.

FIG. 4 is a sectional view of a tape according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Coil conductor, 2 ... Integrated mica prepreg tape, 3
… Glass flake prepreg tape, 4, 6… glass cloth, 5… glass flake.

Claims (4)

[Claims] 1. An insulating system for a rotating machine coil, wherein at least a part of the insulating layer of the coil is wrapped with a non-woven fabric such as glass fiber or a glass flake tape lined with a cloth. 2. The insulating system for a rotating machine coil according to claim 1, wherein after winding the glass flake tape, a thermosetting resin is impregnated by vacuum pressure impregnation treatment and heat-cured. 3. The insulation of a rotating machine coil according to claim 1, wherein a glass flake tape of a prepreg impregnated or adhered with a thermosetting resin is used to wind the coil, and then the resin is heated and cured by a mold. system. 4. An insulation system for a rotating machine coil according to claim 1, wherein the mica tape is wound inside the glass flake tape.